Diffusion-weighted imaging of white matter abnormalities in patients with phenylketonuria

Phenylketonuria (PKU) is an autosomal recessive disorder caused by a defici ency of the enzyme phenylalanine hydroxylase (EC 1.14.16.1). Affected patie nts develop elevated plasma and tissue levels of phenylalanine and its rela ted ketoacids. Untreated patients usually exhibit severe mental retardation and poor motor function, with characteristic T2 white matter signal abnorm alities on conventional NIR images. In the present study, we performed diff usion-weighted imaging in three PKU patients. All three patients demonstrat ed significantly restricted diffusion in all white matter areas examined.